Chain-clasp



T. J. POLLARD AND DARLING.

CHAIN CLASP.

APPLICATION FILED JULY 12, 1920.

' Patented Nov. 30, 1920 INVENTORS WITN ESOECJ.

am {gum AT RNEY.

. UNITED-STATES rATENr;- io F1cE.

THOMAS J. POLLARID, or cRAnsron, AND LEwrs s. DARLING. or PROVIDENCE,

' 'BHODEISLAN-ll V CHAIN-CLASP.

' Specification of Letters Patent. Patented NOV. 30, 1920.

Application filed July 12, 1920. Serialii'o. 395,754.

T all whom it may concern:

Be it known that we, THOMAS 'J. POLLARD and Lnwrs S. DARLING, citizens of the United States, residing at Cranston and Providence, respectively, in the count of Providence and, State of Rhode Island, ave invented certain new and useful Improvements in Chain-Clasps, of which'the following is a specification.

Our invention relates to improvements in chain clasps, .such as areused for ornamental'chains as ordinarily worn about the neck and for chains used for other similar purposes, and the purpose of our invention is to provide a clasp that is cheaply made, quickly engaged, and that will hold the ends of the chain firmly together until removed by the wearer. We accomplish these purposes bythe device shown in the accompany ing drawings, in Which--v Figure l is a plan vi member of the clasp.

Fig. 2 a section of the receiving member, together with the entering member after engagement, and f i v Fig. 3 a cross-section-on the line w-w of Fig. 2. I

In Fig. 1, A represents a spiral or hollow helix formed of ordinary round jewelers wire of gold or any other suitable material. As shown in Fig. 2 in section, the spaces I between thewires in the interior of the helix form in efl'ect-a femalescrew and from the nature of a helix this screwis of flexible or expansible character. The helix isattached' to one end of the chain in any suitable manner. r I

The entering member B is attached to the other end of the chain and consists of a tapering flattened piece, preferably of metal, having serrated edges as shown in Fig. 2, the projecting teeth being of such shape andposition as to engage what answers to the'interior threads, formed by the helix in the manner aforesaid. .The member B is inserted into A in the same manner as a screw is inserted into a nut, and is revolved in the ordinary manner until the engagement is complete. By virtue of the fact that A is in the form of a spiral, and is thereew of the receiving numbers at a trifling 7 thin,

fore expansible and yielding, and that B is tapering, as shown 1n the drawlng, 1t follows that as the member B is screwed into the member A, the latter expands at its tance in our invention.

It is evident that the spaces between the teeth on the edges of the member B need not be exactly as shown in the drawing as one or more teeth may be omitted, all that is required being a suflicient number of teeth properly spaced so as to make proper engagement between the spirals of the member A.

In Fig. 3 is given a cross-section through the combined receiving member A and the entering member B. In this figure C represents a cross-section of the wire composing the helix. The dotted line a represents the expanded circle due to the entrance of the tapering member B.

The flattened member B, as shown in the drawings, can be stamped upon an ordinary jewelers press from flat stock in enormous expense, without the use of special machinery. Having now described our invention, what we claim and desire to secure by Letters Patent is 1. In a chain clasp, an entering member, tapering longitudinally,- and adapted to enter and by its tapering form, expand a flexible receiving member, substantially as set forth. v

2. In a chain clasp, an entering member consisting of a flattened body relatively tapering longitudinally and provided with serrated edges, the serrations being so spaced as to on age a part of or all the spaces between t e coils of a helical receiving member, substantially as described.

3. A chain clasp comprising a flexible rea flattened longitudinally tapering entermg tures in presence of tWO Witnesses;

coils of the eneeeivingmember, substantially ceiving member cf hollow helical form; and In testimonywhefeof We afiix our isignamember ada ted to be struck u out of fiat V stockzan d pn vided \Withi-sennate l eiilges,:ifihe- V i serrations being so spaced as to engage a '7 V 3 part of or all the spaces between the helical Witnesses:

'1EDI-'IJH;M. BR0MLEY;

as specified. I HENRY J, BLAIs, Jr. 

